NHS hospitals face paying millions in compensation to family members whose loved-ones undergo botched medical procedures after a grandmother successfully claimed for suffering PTSD following the birth of her granddaughter.

Experts say the High Court ruling “turns the tide” in favour of family members claiming compensation in cases of medical negligence.

Calderdale & Huddersfield NHS Foundation Trust were ordered to make the pay-out after a chaotic delivery which left the new-born with permanent neurological damage.

The unnamed baby, which came out “flat and purple with a swollen head”, did not start breathing for 12 minutes – her mother and grandmother believed she was dead.

Until now, family members traumatised from witnessing negligent medical procedures or their aftermath have found it extremely difficult to successfully claim damages.

While patients groups have welcomed the new ruling, it could mean health bosses, wary of large legal bills, start limiting the number of relatives present during hospital procedures.

Nigel Poole QC, head of King’s Chambers and a medical negligence specialist, said: “I would not underestimate the importance of this decision.

“There are potentially a lot of people who could bring a claim like this.”

The High Court found the midwives at Calderdale Birthing Unit did not properly anticipate the risk of delivering a 10lbs baby.

The girl suffered an acute profound hypoxic ischaemic insult as a result of an unnecessary 11-minute delay in delivery in April 2011.

Mr Justice Goss also found the midwives had deliberately prevented a specialist obstetrician from entering the room during a crucial stage in the emergency, and that the hospital subsequently destroyed medical records after the legal action had begun.

The mother had raised concerns about the size of her baby during antenatal appointments, but the “offhand” midwives had told her “big babies just slip out”.

In the event, the girl’s shoulder became jammed behind her mother’s pelvic bone.

Historically, courts have been very reluctant to award damages to family members who witness traumatic scenes in hospital on the basis that it would open the floodgates to thousands of claims, and that relatives should expect a degree of unpleasantness when they go to hospital.

However, Mr Justice Goss found that watching a complicated birth which resulted the appearance of a stillborn baby was “sufficiently horrifying” for both mother and grandmother to claim for PTSD.

Suzanne White, a medical negligence expert at Leigh Day, said that hospital chief executives normally try their best to settle these types of case behind closed doors because they want to avoid setting a precedent.

“This ruling puts the cat among the pigeons,” she said. “The NHS don’t like this kind of case because there could be a huge number of them.”

Rolf Dalhaug, of the campaign group 17 Dads, had to fight for compensation for his PTSD when one of his twins, Thor, lost his life during a delivery using forceps at Lincoln County Hospital in 2013.

Last night he welcomed the new ruling recognising the effect medical negligence can have on close family.

“The NHS don’t recognise it at all, I think it’s something they choose to actively supress,” he said. “I think this ruling is massively important and will have a big effect going forward.”

Calderdale & Huddersfield NHS Foundation Trust has said it will appeal against the decision.

Line from trust: "The trust recognise and regret that a number of lives have been adversely affected by the events of this case."